Consider the titration of a 25.0-mL sample of 0.115 M RbOH with 0.100 M HCl. Determine each quantity. c. the pH at 5.0 mL of added acid

Verified step by step guidance

1. Calculate the initial moles of RbOH using its concentration and volume: \( \text{moles of RbOH} = 0.115 \text{ M} \times 0.025 \text{ L} \).
2. Calculate the moles of HCl added using its concentration and the volume added: \( \text{moles of HCl} = 0.100 \text{ M} \times 0.005 \text{ L} \).
3. Determine the moles of RbOH remaining after reaction with HCl by subtracting the moles of HCl from the initial moles of RbOH.
4. Calculate the concentration of the remaining RbOH in the total volume of the solution (initial volume of RbOH + volume of HCl added).
5. Use the concentration of the remaining RbOH to find the pOH, and then convert it to pH using the relation \( \text{pH} = 14 - \text{pOH} \).

Key Concepts

Titration

Titration is a quantitative analytical technique used to determine the concentration of a solute in a solution. It involves the gradual addition of a titrant (a solution of known concentration) to a sample until a reaction is complete, often indicated by a color change or pH change. In this case, RbOH, a strong base, is being titrated with HCl, a strong acid.

pH Calculation

pH is a measure of the acidity or basicity of a solution, calculated as the negative logarithm of the hydrogen ion concentration. In a titration, the pH changes as acid is added to a base. At the equivalence point, the pH is neutral, but before that point, the pH can be calculated using the concentrations of the remaining acid and base in the solution.

Stoichiometry of Acid-Base Reactions

Stoichiometry in acid-base reactions involves the mole ratio of the acid and base reacting together. For strong acids and bases, the reaction is complete and can be represented by a balanced equation. In this case, the reaction between RbOH and HCl will determine how much of each reactant is present at various points in the titration, which is essential for calculating the pH at specific volumes of added acid.